Synthetic stone products are well known and are in great demand due to their ability to be manufactured in a wide variety of shapes, patterns and colors that cannot be consistently found in nature. Such compositions are for example described in U.S. Pat. Nos. 4,664,954, 4,085,246, 4,678,819, 4,734,452, 5,043,377 and 5,055,327. Synthetic stone compositions generally contain from 50 to 80% by weight of mineral particulate in a crosslinked resin matrix. The disadvantage of the described stone compositions is that when molded they result in surfaces which reflect the properties of the resin more than the properties of the mineral particulate contained in the compositions.
Engineered stone compositions on the other hand resemble natural stone to a greater degree but have much better fabricability compared to natural stone and are useful in slab or sheet form in both interior and exterior walls of buildings, indoor and outdoor floors, fireplaces, table and counter tops, tiles and an assortment of other uses for natural stone. Engineered stone compositions contain a higher percentage of a mineral particulates, generally in the range of 80 to 95% by weight, in a resin matrix as compared to moldable synthetic stone compositions and provide a stone-like surface. Such compositions are described in U.S. Pat. Nos. 6,387,985 and 7,727,435. The disadvantage of known engineered stone compositions is the limited means of producing the composite and the shape of the products obtained. Engineered stone is formed by casting methods and requires both vibration and a vacuum in order to obtain a properly compacted, bonded structure of the mineral particulate and to eliminate any entrapped air. Casting can be a serious problem in commercial manufacture of the slabs since it is a batch process subject to property variations from batch to batch. Casting methods furthermore require extensive set up and cleanup operation in order to resume production after completion of a run.